centrifugal forces are reacted against the rotor disk and produce stresses. The idea is to make the disk thick enough to keep the average stresses way below the yield strength of the material and allow for margins with the UTS of 50% or more.
Assuming everything remains in balance the aircraft and passenger never feel centrifugal force no matter how big the engine.
In a blade out situation the unbalance forces created by the remaining blades still spinning react against the bearing supports and ultimately the engine mounting and the wing. These forces as direct loading are quite large but are easily accomodated with a couple of square inches of solid metal between the engine and the wing. Unfortunately the cyclic effect is enough to make your teeth rattle
The forces generated against the case when a blade comes loose are not realistically calculable since they are determined by the rate of decelleration (several micro-seconds) and even then are only felt extremely locally by the case material. The containment itself is closely related to a ballistic impact event (like a bullet against armour) and is pretty much an energy balance between the case material potential energy and the blade moving at about half the speed of sound. The idea here is to make the impact last long enough to use the potential energy in the case material and not have it shatter.